Electrocardiographic Findings Among Major League Soccer Athletes: Normative Data From a Diverse Population

Abstract

Background: Major League Soccer (MLS) is composed of an ethnically diverse athlete population for which electrocardiogram (ECG) analysis has not been previously reported.

Objectives: This paper evaluated MLS player ECGs and characterized ECGs as having normal, borderline, and/or abnormal ECG findings based on the international criteria. Echocardiographic data were analyzed when history, physical, or ECG findings were abnormal.

Methods: This was a cross-sectional study of MLS players from 2017 to 2020.

Results: A total of 706 athletes were included in this study. Athletes were predominantly Caucasian 346 (49%), followed by Black, 85 (26%), and Hispanic, 175 (25%). The mean (SD) age was 24.5 (4.3) years with an age range of 15 to 37 years. The most common abnormal ECG finding was T wave inversion (TWI) (total percent of TWI). Black athletes had a greater proportion of ECGs with any isolated TWI, with 11.9%, compared to Caucasian (5.2%, P = 0.005) and Hispanic (5.7%, P = 0.040) athletes. Subgroup analysis of those with abnormal TWI revealed mostly structurally normal hearts. The most common borderline finding was left axis deviation, with Black athletes having a statistically greater proportion of left axis deviation when compared to Caucasian athletes (3.8% vs 1.2%, P = 0.043). Training-related ECG changes are highly prevalent among professional male soccer players regardless of race.

Conclusions: The most common ECG abnormality and borderline finding per international criteria are TWI and left atrial enlargement, respectively. Both were more prevalent in Black athletes. Echocardiography did not reveal underlying cardiovascular disease during follow-up even in the presence of abnormal ECG findings.

Keywords: T wave inversions black athletes; athlete ECG changes; black athlete ECG; sports cardiology.

Graphical abstract

Central Illustration

Major League Soccer Athlete Electrocardiogram Finding by International Criteria When analyzing MLS athletes’ ECGs, 10% of athletes have at least 1 abnormal and/or ≥2 borderline findings per international criteria. Abnormal findings by race revealed Black athletes have the highest prevalence of abnormal findings (13.0%), followed by Hispanic (9.1%) and then Caucasian athletes (6.4%). Abnormal T-wave inversions are most prevalent in Black athletes (11.9%). ∗Athletes characterized as having an abnormal ECG include ECGs meeting at least 1 abnormal and/or ≥2 borderline criteria as defined by IC. ∗∗This includes ≥1 abnormal ECG finding. ∗∗∗Abnormal TWI in African athletes is characterized as TWI in lead V₄ and beyond and/or the inferior leads. ECG = electrocardiogram; IC = International Recommendations for Electrocardiographic Intepretation in Athletes; MLS = Major League Soccer; TWI = T wave inversion.

Figure 1

Abnormal Electrocardiogram Subgroup Analysis Bar graph representation of the percentage of abnormal ECGs by age, race, LVEDD, RWT, and PR interval. ECG = electrocardiogram; LVEDD = left ventricular end diastolic dimension; RWT = relative wall thickness.

Figure 2

Abnormal T Wave Inversion Subgroup Analysis Bar graph representation of prevalence of abnormal TWI by age, race, LVEDD, and RWT tertiles. TWI = T-wave inversion; other abbreviations as in Figure 1.

Figure 3

Abnormal Electrocardiogram Echocardiographic Findings Box-and-whisker plot representation of LVEDD and RWT for athletes who have abnormal ECGs per international criteria by racial criteria subgroup analysis. Abbreviations as in Figure 1.